(16) compared 1380 women with BRCA1/2 mutation with breast cancer history to 1380 women with BRCA1/2 mutation carriers without breast cancer history and found no difference between exposure to ovarian stimulation and breast cancer risk (OR: 0.98, 95% CI: 0.39–2.45), while exposing to gonadotropin-containing fertility treatment showed a nonsignificant increase risk of breast cancer (OR: 2.32, 95% CI: 0.91–5.95). This evidence concerns the gene BRCA1 and breast cancer.